The present invention relates generally to electrical and mechanical connection of electrical components. The present invention more particularly relates to method and apparatus for locating a liquid crystal display connector on a liquid crystal display (LCD).
LCDs are commonly used to provide operational information to users of electronic equipment such as personal computers, personal digital assistants, and cellular telephones. LCDs are manufactured according to well-known processes. An LCD typically is manufactured using a glass plate with an active area on which the information may be displayed. The LCD is contained in a housing of the electronic equipment. The active area is visible through a window defined in the housing.
To increase user convenience, the size of the active area is preferably maximized. One result of this is that the edge of the active area is near the edge of the window. However, when the active area is large, even slight misalignment of the LCD is very apparent to the user.
Many opportunities for LCD misalignment exist. In a typical application, the glass plate of the LCD is retained in a carrier or light guide. The carrier or light guide is fastened to a printed circuit (PC) board. The PC board is mounted in the electrical equipment. Each of these interconnections has a manufacturing tolerance. Misalignment of any of these interconnections can result in misalignment of the active area relative to the window.
Each interconnection of these mechanical components has a nominal alignment and an associated tolerance. The largest manufacturing tolerance is typically the size of the LCD glass plate. Such glass plates are conventionally formed by scrolling and breaking and as a result have a tolerance of .+-.0.2 mm.
The total tolerance sum for the interconnections is .+-.1 mm, but the maximum permissible tolerance between the active area and the window is .+-.0.5 mm. Any misalignment greater than this is visible to the user and will cause rejection of the finished product or require repair before the product can be sold. Those are both expensive steps and are preferably avoided.
Accordingly, there is a need to improve the location of LCD plates in electronic equipment.